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When to plant Pumpkin in Adams County County,

Adams County County gardeners should plant Pumpkin between May 1 and May 22 in spring. With Adams County County's Zone 5b climate (last frost April 24), Pumpkin needs 120 days to mature — plant by June 13 for a full harvest.

When to Plant Pumpkin in Adams County, IA

Pumpkin
Adams County, Iowa Zone 5b June

June in the garden — Adams County, Iowa

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Adams County, Iowa.

Avg. last frost April 24
Avg. first frost October 11
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 14.9 hrs

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Pumpkins are large-fruited squash varieties grown for eating, decoration, and seed production. They require ample space and a long, warm growing season.

Adams County, Iowa is in USDA Zone 5b. The average last spring frost is April 24 and the first fall frost is October 11, giving you a growing season of approximately 170 days.

At an elevation of 998 feet, Adams County receives approximately 32.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Pumpkin during the growing season.

Adams County, IA (Zone 5b) Moderate season
170 days
Last Spring Frost April 24
170 growing days
First Fall Frost October 11
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Adams County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.2

Drainage

Well Drained

Pumpkin Planting Risk Windows

Early Start (70% safe) ✓ Fits season (16 days to spare)
Start indoors: Mar 14 Transplant: May 2 🍅 Harvest: Aug 1 – Sep 19
Recommended (50%) ✓ Fits season (16 days to spare)
Start indoors: Mar 20 Transplant: May 8 🍅 Harvest: Aug 7 – Sep 25
Safe Start (90%) ✓ Fits season (15 days to spare)
Start indoors: Apr 3 Transplant: May 22 🍅 Harvest: Aug 21 – Oct 9

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Adams County

How your county's soil matches Pumpkin's growing requirements.

Soil pH

Your soil pH (6.1–7.2) is within Pumpkin's preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Adams County is excellent for Pumpkin — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.8%) — Pumpkin will thrive.

How to Plant Pumpkin

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Pumpkin Water Budget

Plant needs
1.3″/week
Rainfall provides
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 920 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Pumpkin

Pumpkin needs approximately 1.3 inches of water per week (5.6" per month). Here's how your county's rainfall compares month by month.

Month Pumpkin Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 5.6" 3.1" 2.5" 💧 Light watering
May 5.6" 4.3" 1.3" 💧 Light watering
Jun 5.6" 3.8" 1.8" 💧 Light watering
Jul 5.6" 3.4" 2.2" 💧 Light watering
Aug 5.6" 3.2" 2.4" 💧 Light watering
Sep 5.6" 2.9" 2.7" 💧 Light watering
Oct 5.6" 2.6" 3" 🚿 Regular watering
Nov 2" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Adams County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Pumpkin Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Pumpkin needs ~1,486 GDD — county provides 2,465 GDD Excellent fit

Pumpkin Planting Timeline — Adams County, IA

Pumpkin Planting Calendar

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors May 8 May 8 – May 22
Direct Sow May 1 May 1 – May 22
Harvest August 7 Aug 7 – Sep 25

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June
July
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.3"/week · 1-2 times/week

📅 Days to Maturity

85–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

170 days in Adams County

Growing Tips for Pumpkin in Adams County

Direct sow Pumpkin outdoors after April 24 in Adams County when soil has warmed and frost danger has passed.

Common pests for Pumpkin in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow on mounds after last frost. Allow 6-10 feet between plants. Slip a board under developing fruit to prevent rot. Harvest when rind is hard and deep in color.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Pumpkin in Adams County, IA?

Adams County is in Zone 5b with an average last frost of April 24. Plan your Pumpkin planting based on this frost date — see the calendar above for exact timing.

What planting zone is Adams County, IA?

Adams County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 24 and first fall frost is October 11.

When should I plant Pumpkin in Adams County County, ?

In Adams County County, , plant Pumpkin after the last frost (around April 24) and before the first frost (around October 11). Best results when soil holds above 50°F.

What growing zone is Adams County County, for Pumpkin?

Adams County County sits in USDA Zone 5b. Pumpkin grows reliably in zones 3a through 10b, so it's a good fit here.

Can Pumpkin grow in Adams County County's climate?

Yes — Pumpkin grows well in Adams County County's temperate climate. Adams County County averages a 170-day frost-free season, with last frost around April 24 and first frost around October 11.

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Your Adams County Garden Planner — Free

A 22-page printable planner built for Adams County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Adams County, IA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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